282 HE MARQUETTE IRON-BEARING DISTRICT. 



alone. Between tlie brecciated slates and those in whicli there is merely 

 a development of slatiness or schistosity, with secondary ferrugination and 

 silicification, theVe are all gradations, so that there is positive proof of the 

 brecciated character of the rocks. 



About the other two Archean islands in sees. 22 and 23, are interesting 

 exposures of conglomerate, slate, and graywacke, but as these are not very 

 different from those already mentioned, they will not be further described. 

 The conglomerates, slates, and graywackes are particularly well developed 

 about the corner between sees. 21, 22, 27, and 28, and also to the east and 

 northwest of this point. 



SECTIOK^ IV.— THE AJIBIK QUARTZITE. 



The formation is given the name Ajibik quartzite because the predom- 

 inant rock is quartzite, and because typical exposures of it occiu- on the 

 bold Ajibik Hills northeast of Palmer (Atlas Sheet XXXII). 



DISTRIBUTION, EXPOSURES, AND TOPOGRAPHY. 



Beginning at the south arm of Goose Lake (Atlas Sheet IV), the forma- 

 tion occupies a broad belt, which narrows in sec. 23, swings south of the 

 Wewe slate, and then gradually increases in width to sec. 28, T. 47 N., 

 R. 26 W. From this place one arm extends to the west for nearly a mile, 

 but the main arm swings to the north, west of the Wewe slate, and then 

 east, nortli of the same formation. AVest of Goose Lake the belt again 

 becomes broad, and an arm projects to the southeast between two Archean 

 islands, being bounded on both the east and the west by the Wewe slate. 

 The main belt, reaching Goose Lake, extends north of this area for a mile, 

 then swings eastward, which course it follows for 2 or 3 miles, then swings 

 to the northeast to Carp River. Here it is faulted, but, reappearing again 

 north of the river, it continues its course east, then north, then west in 

 sec. 6, T.^ 47 N., R 25 W. It follows this western course to the quartzite 

 range east of Teal Lake, the southern part of which it constitutes. West 

 of Teal Lake it reappears, here being in contact with the Archean, and 

 follows alonor this formation to Lake Michigamme. 



